How can I change type of column

Can I change type of column with alter table command?

For instance if I have a table t1 and column c1 which is defined as
decimal(18, 2) and I want to change it into decimal(18, 3) in MS SQL
server I can write:

alter table t1 alter column c1 decimal(18, 3)

Is there something similar in PostgreSQL? Tnx in advance.

Dragan